In order to increase productivity and reduce cost of ownership, substrate processing systems have been developed that process multiple substrate simultaneously. This has been done conventionally by using process chambers that can process multiple substrates in a common volume. However, the inventors have discovered that uniformity issues may arise when using multiple substrates in a common volume that do not arise in single substrate processing systems. In addition, the inventors have observed that conventional single substrate processing systems are unable to satisfactorily share chamber resources, thereby frustrating attempts to reduce the cost of ownership and increase process throughput.
Accordingly, the inventors have provided methods for processing substrates in twin chamber processing systems using shared chamber resources.